package Day07;
import java.util.Random;
public class VerificationCode {
    public static void main(String[] args) {
        String code = veriCode(4);
        System.out.println("验证码为："+code);

    }
    //生成验证码
    public static String veriCode (int _length) {
        String code = "";
        char[] charCode = {'a','b','c','d','e','f','g','h','i','j','k','l',
                           'm','n','o','p','q','r','s','t','u','v','w','x',
                           'y','z','A','B','C','D','E','F','G','H','I','J',
                           'K','L','M','N','O','P','Q','R','S','T','U','V',
                           'W','X','Y','Z','0','1','2','3','4','5','6','7',
                           '8','9'};
        Random rand = new Random();
        for (int i=1;i<=_length;i++) {
            int index = rand.nextInt(charCode.length);
            code += charCode[index];
        }
        return code;
    }
}
